Paper slide rule calculator



March 20, 1962 J. B. RUFFALO PAPER SLIDE RULE CALCULATOR 2 Sheets-Sheet 1 Filed Feb. 18, 1959 Jepma 'iwsaaw BY TTORNES ullulHIlHlHlu.

J. B. RUFFALO PAPER SLIDE RULE CALCULATOR March 20, 1962 2 Sheets-Sheet 2 Filed Feb. 18, 1959 INVENTOR JoFvnBfRuffalc EATTORNEZS I United States Patent M 3,025,767 PAPER SLIDE RULE CALCULATOR John B. Rufifalo, 1 Forestdale Drive, Huntington, N.Y. Filed Feb. 18, 1959, Ser. No. 794,079

2 Claims. (Cl. 93-1) This invention relates to slide rule calculators formed by folding a single piece of paper and selectively coating the folded paper to produce in one operation both the slide and the guide walls.

According to the present invention holes of predetermined sizes and locations are formed in a strip of paper of uniform width. A pair of adhesive stripes is placed on one surface of the paper but only along the two edges thereof, and one section of the paper is scored adjacent the two adhesive stripes, the scoring being parallel to the longitudinal direction of the strip of paper so as to separate the adhesive coated edges of the scored section from the central part of that section. The strip is then folded twice to cause the adhesive material to adhere to overlapping surfaces of the paper and in such a way that the scored section is between the other two sections. The paper is then cut approximately along the folded lines and in such a way as to sever the interior piece from the two outside pieces and from its adhesive coated edges as well. The interior piece thus becomes a slide of a slide rule while the outer pieces become the guides therefor and the adhesive coated edges originally attached to the interior piece become spacers to allow the interior piece to slide freely in the guides.

One of the objects of the present invention is to provide a simple method of making a slide rule, particularly a slide rule of a disposable type.

Another object is to make a slide rule of paper and to provide a method of folding the paper in such a way as to form a spacer equal in thickness to the thickness of the slide so as to permit the slide to work easily in its guide.

A still further object is to provide a method of making a paper slide rule and an attached letter of one piece of paper by selectively folding the paper.

Further objects will be apparent from the following specification together with the drawings in which:

FIG. 1 shows a slide rule calculator construction according to the invention;

FIG. 2 shows a cross sectional view of the calculator of FIG. 1;

FIG. 3 shows a piece of paper printed and scored for making the calculator of FIG. '1;

FIG. 4 shows the first step in folding FIG. 3;

FIG. 5 shows the second step of folding the paper of FIG. 3;

FIG. 6 shows a completely folded calculator prior to the step of cutting the ends;

FIG. 7 shows a piece of paper similar to FIG. 3 and including an additional paper section suitable for a letter; and

FIG. 8 shows a complete slide rule calculator and letter produced from the paper of FIG. 7.

The slide rule of FIG. 1 comprises an upper paper guide 11 imprinted with suitable indicia 12 and 13 for performing calculations. At least one window is cut into the paper 11, and in the embodiment shown two such windows 14 and 16 are provided. The ends of the paper 11 have thumb holes 17 and 18 to provide access to a slide 19 which is of the same overall length as paper 11 and is formed from the same sheet of paper. Slide 19 bears indicia 21 and 22 which cooperate with the indicia 12 and 13 to permit calculations to be made.

FIG. 2 shows a cross sectional view of the calculator of FIG. 1 and indicates the front paper guide 11, a back the paper of 3,025,767 Patented Mar. 20, 1962 paper guide 23 which may also be provided with windows if desired, and two paper spacer members 24 and 26 which are the same thickness as the slide 19 and which therefore assist in the ease of operation of the slide between the guiding papers 11 and 23 by preventing the slide from becoming wedged between the guides.

In order to form the calculator of FIG. 1 a strip of paper slightly more than three times the length of the finished slide rule is first cut as shown in FIG. 3. In FIG. 3 the section 111 of the paper strip 27 which later becomes the front paper guide 11 is in the center of the strip, section 119, which later becomes slide 19 is at the left end, and section 123, which later becomes the back guide 23, is at the right. Indicia on the slide section 119 which will be subsequently visible through Windows 14 and 16 appears on the surface of section 119 shown in FIG. 3, but cooperating indicia on section 111 is printed on the reverse side and is not visible in this View. If sections 111 and 123 were interchanged, all printing could be done on one surface of strip 27.

Windows 14 and 16 and thumb holes 17 and 18 are cut out of section 111 and section 123 has cut out apertures 18a and 17a which match the thumb holes 17 and 18 of section 111. Section 119 of the paper strip 27 in cludes the spacer strips 24- and 26 as well as the slide 19. Slide 19 and the spacers 24 and 26 are formed by scoring section 119 along the lines 28 and 29 for a length slightly greater than will be the final length of the slide 19. This final length is indicated by lines 31 and 32 and corresponds to the final length of front paper 11 which is indicated by lines 33 and 34 and to the back paper 123 which is indicated by lines 36 and 37. Two stripes 25 and 30 of adhesive material are laid down on one side of the paper strip 27 along both edges thereof. The width of these stripes is not greater than that of spacers 24 and 26 so that none of the adhesive gets on what will later be slide 19.

The order of folding paper strip 27 is important and the first step of this folding is shown in FIG. 4. In this step section 119 of the paper strip 27 is first folded over in the direction of the arrow 38 to lie flat against section 111. In this way the portion of adhesive stripes 25 and 30 on one surface of the spacers 24 and 26 will be pressed against the portion of the adhesive stripes 25 and 36 on section 111 so that the latter section of the paper strip 27 becomes the front paper surface 11. Preferably the adhesive is of a pressure-operated type so that merely by pressing the folded sections of the paper strip 27 together the spacers 24 and 26 will be bonded to the edges of section 111.

FIG. 5 shows the next step in the folding process. In this figure the back surface section 123 is folded in the direction of the arrow 39 against the spacers 24 and 26 and the slide 19. While there is no adhesive material on the rear surface of spacers 24 and 26, the strength of the adhesive material in the portion of the stripes 25 and 30 on section 123 is suificient to cause the contiguous portions of section 123 to adhere to the spacers 24 and 26.

FIG. 6 shows paper strip 27 folded into a slide rule calculator. It will be seen from this drawing that the slide rule calculator is complete except that it is impossible to move the slide 19 for the reason that it is attached at the left hand end to the front paper guide 11 and at the right hand end to the back paper guide 23. All that remains is to pass the folded paper strip 27 between two pairs of cutting rollers 41 and 42 which are spaced apart a distance indicated by lines 36 and 37 on the back surface of paper 23. By so doing the folded ends of all sections of the paper strip 27 will be severed and the slide 19 will be free to move between the front and back guides 11 and 23.

'lndicia can be printed on the back surface of the slide 19 as well as on the front surface, and if it is desired, the printing on the two surfaces can be aligned and correlated so that both sets of indicia can be used at the same time to make a more complex calculation than could be carried out'by using the front surface alone. Normally, if there are indicia on the back surface of the slide 19, corresponding windows should be cut in the back guide 23 to cooperate withindicia on the slide in making a calculation. However, in some cases one end of the back guide 23 could be used as a stationary cursor in place of a window.

In many instances it is desirable to enclose with the calculator an advertising letter and in so doing it is preferable to prevent the letter and calculator from becoming separated. In this way maximum advantage may be taken of advertising information written in the letter. FIG. 7 shows a paper strip which includes a section 127 similar to paper strip 27 in FIG. 3 and another section 43 on which a letter may be written. Since the section 127 is part of the same piece of paper as section 43, the two will remain together, even in the hands of a recipient. Sections 211, 219 and 223 correspond to similar sections 111, 119 and 123, respectively, of paper strip 27 in FIG. 3 and the process by which these sections are folded will therefore not be described again. In addition to section 43 a second page of the letter may be made available if an additional section 44 is provided. In such a case sections 43 and 44 will have to be severed along line 46 after the calculator has been folded according to the foregoing description.

The final result of a combined letter and calculator formed according to FIG. 7 is shown in FIG. 8. As in the case of the slide rule of FIG. 1, the sections 211 and 223 may be interchanged in order to permit all printing to be done on one side of the sheet of paper. Also indicia could be printed on both surfaces of the slide 219 and separate windows cut in both sections 211 and 223.

While the term paper has been used throughout, it is not to be construed as being limited to soft paper, alone, but also includes hard papers, such as, for example, index, Bristol, and tag stock, as well as plastics having similar characteristics suitable for the purpose. The durability of several of these materials is such that a slide made from them could last quite a longtime and yet be inexpensive enough to use freely as an advertising device.

While there has been shown a preferred embodiment of the invention, it is to be understood that many changes may be made therein without departing from the essential spirit of the invention as set forth in the annexed claims.

,What is claimed is:

1. A method of making a paper slide rule comprising the steps of printing indicia on one side of a first section of a strip of paper, said strip of paper being approximately three times the length of said first section and having two additional sections which are approximately equal in length to the length of said first section and which extend in immediate succession from one end of said first section, each of the three sections aforesaid being slightly longer than in the finished slide rule, forming at least one window in one of said additional sections, scoring said first section by cutting two longitudinal slits substantially parallel to each other and slightly less than the length of said first section but greater than the length of the-slide of said slide rule to divide said first section into a central slide and two spacers at the edges of said slide, applying a stripe of adhesive material along each longitudinal edge of one surface of said strip extending throughout the entire length thereof, the width of each of said stripes being no greater than the width of said spacers whereby said adhesive material is applied along each longitudinal edge of said strip but not to said slide, folding said first section relative to the section immediately contiguous therewith to bring the latter section into face-to-fac'e' contact with one side of said first section with said stripes of adhesive material carried by each of said sections therebetween, sealing said sections together by means of said adhesive material, thereafter folding the third of said three'sections relative to the other two sections after said other two sections have been folded as aforesaid to bring it into face-to-face contact with the other side of said first section with the stripes of adhesive material carried by said third section between said third section and said other side of said first section, sealing said third and first sections together by means of said adhesive material, said Window being formed in the section that is folded into face-to-face contact with the side of said first section on which said indicia are printed, and cutting off both ends of the folded strip to free said slide for longitudinal movement back and forth in the space defined by the sections on the opposite sides of said first sectionand by said spacers whereby said indicia on said first section appear selectively in said window as said slide is moved to selective positions Within said space.

2. A method according to claim 1 wherein said strip of paper constitutes the cross bar of a T with respect to another paper section integral with one of the longitudinal edges of the section of said strip adjacent said first section.

References Cited in the file of this patent UNITED STATES PATENTS 

